Force moment sensor

ABSTRACT

The force moment sensor is a monolithic disk-shaped mounting part ( 20 ) including a flat surface. The mounting part includes a first middle portion ( 21 ) of high rigidity with first force application locations ( 25 ), at least three second portions ( 22   1  to  22   3 ) of medium rigidity configured circumferentially, each including two second force application locations ( 26 ) in the transition portion between juxtaposed second portions, strain relief portions ( 23 ) of low rigidity and at least three radially oriented connecting webs ( 24 ) and comprising a medium rigidity by a recess ( 27 ) of U-shaped cross-section being configured in the medium portions thereof. Mounted on the flat surface of the second portions ( 22 ) and of the connecting webs ( 24 ) are strain gauges ( 28 ) circuited in accordance with the principle of a Wheatstone bridge. From the measured values obtained thereby three forces (F x , F y , F z ) and three moments (M x , M y , M z ) can be defined.

[0001] The invention relates to force moment sensors.

[0002] In precision manipulation of a robotic hand, high demands areplaced on a so-called smart multidimensional force moment sensorprovided in the finger tips of the robotic hand. On top of this, thegreatly restricted space available in the finger tips calls for a sensorconfigured highly compact mechanically.

[0003] Known from DE 100 13 059 C2 is a force moment sensor on a roughlycircular ring-shaped mounting part comprising at least three flexurallyrigid portions configured equal in size and equally angularly spacedcircumferentially on the mounting part, at least three flexible portionsbetween said flexurally rigid portions and at least three connectingwebs each oriented radially from said flexible portions.

[0004] These connecting webs are connected to an axially symmetricalrigid supporting part oriented perpendicular to the middle plane of themounting part located, for example, in the xy-plane of a system ofCartesian coordinates. Mounted on the force moment sensor are preferablytwo strain gauges forming a strain gauge pair on each flexible portion.

[0005] These strain gauges are circuited on the principle of aWheatstone bridge as a quarter, half or full bridge so that thecorresponding measured values can be derived from the strains orcompressions as sensed by means of the strain gauges under load. Fromthese measured values a total of three components, namely the momentsM_(x) and M_(y) generated in the middle plane corresponding for exampleto the xy-plane and a force F_(x) acting perpendicular thereto, i.e. inthe direction of the z axis, are determined in a data signal processingmeans.

[0006] To determine, in addition to the force F_(x) the two furtherforces F_(x) and F_(y) acting in the direction of the x axis and y axisat least four further strain gauges are provided on the axialsymmetrical part oriented parallel to the central axisthereof—corresponding to the z axis. To also determine the moment M_(z)four strain gauges are oriented on the axial symmetrical supporting partat an angle to the central axis thereof.

[0007] The drawback with this device as known from DE 100 13 059 C2 isthat parts of this sensor structure, namely, for example, the rigidsupporting part oriented perpendicular to the middle plane of themounting part and the mounting part formed by the radially orientedconnecting webs of this sensor, are joined by being adhesively bonded.This has a negative effect on the measuring accuracy, however, and thusalso on the reliability.

[0008] Furthermore, with these known force moment sensors, correctlymounting the strain gauges, for example, on a cylindrical or outersurface of the axial symmetrical part is complicated and thustime-consuming. It is furthermore a disadvantage that providing thesupporting part in the middle restricts the space available for theelectronics of the analyzer since a hole needs to be provided in themiddle of the printed board.

[0009] In force moment sensors used hitherto the strain gauges forcontacting are soldered by means of thin wires in general to strip linesprovided on a printed board. Furthermore, with force moment sensorscapable of sensing or measuring six components, namely three forces andthree moments the strain gauges are positioned at different locations,especially, however, at different levels and in different layers.

[0010] To analyze the sensed measured values these are first input ingeneral into an analog part in the form of one or more operationalamplifiers. The analog measurement signals as are now amplified are, ingeneral, communicated by cables having to be as long as 5 m before beingput through analog/digital conversion and finally analyzed in acomputer.

[0011] The drawback in this prior art is more particularly that becausethe thin wires needing to be soldered to the strip lines of a printedboard this necessitates, in general, complicated assembly which withvery small force moment sensors, i.e. smaller than 20 mm in diameter,becomes even more complicated since precisely locating the strain gaugestakes up a lot of time. Due to the strain gauges being arranged andpositioned at different levels and in different layers, making use of aflexible printed board is not possible in general. Furthermore,distancing the analog part separate from the digital part in whichanalog/digital conversion is implemented is a disadvantage since thisgreatly adds to the probability of a fault in the sensitive analogsignals communicated.

[0012] One object of the invention is thus to configure force momentsensors very compact and to eliminate the complications in mounting thestrain gauges whilst separately sensing up to six components, i.e. threemoments and three forces all at the same time. A further object,especially as regards very small force moment sensors, is toconsiderably reduce the expenditure in assembly as regards contactingthe strain gauges whilst practically eliminating disturbing factorsdetrimenting communication of the amplified analog signals.

[0013] In accordance with the invention the one object is achieved by aforce moment sensor as it reads from the claims 1 or 2 and also as itreads from one of the claims 3 or 4. In this arrangement, in accordancewith the invention, by means of the force moment sensor as it reads fromclaims 1 and 2 six components, namely three moments and three forces andby means of the force moment sensors as it reads from claims 3 and 4 twocomponents, namely two forces are precisely sensed and subsequentlydetermined.

[0014] Advantageous further embodiments of the force moment sensors formthe subject matter of claims 5 to 11.

[0015] Furthermore, various possible applications of the force momentsensors in accordance with the invention read from the claims 15 to 19.

[0016] The force moment sensors in accordance with the invention arevery compact by being configured as a monolithic mounting part having aflat surface. In the preferred embodiments strain gauges or meansthereof are mounted on this monolithic mounting part in being combinedinto a plurality of measuring bridges in thus enabling a total of sixcomponents, namely three moments M_(x), M_(y) and M_(z) each orthogonalto the other as well as three likewise orthogonal forces F_(x), F_(y),F_(x) to be sensed and determined. In this arrangement the strain gaugesare mounted in a single plane on circumferential portions preferably ona regular center-spacing and in addition on connecting parts orientedradially to the circumferential portions. As a result feedback signalsas to each of the moments and forces concerned can be obtained, asacting on the measuring plane.

[0017] The major advantage of this, as compared to all force momentsensors known hitherto, is the low-profile compact configurationachieved and especially in enabling the measurement matrices to bemounted in a plane. It is the advantage of this configuration of theforce moment sensors in accordance with the invention that, in additionto the usual method of adhesive bonding the strain gauges in place,other alternative methods can find application, because hitherto, thefree access to the surface(s) for mounting the strain gauges as neededfor these methods is now made available and assured for the first timeby these embodiments in the force moment sensors in accordance with theinvention.

[0018] Force moment sensors in accordance with the invention can thus beput to use preferably in at least one tip of a robotic hand or also inmedical systems especially where related to minimal invasive surgery(MIS). In making use of the principle forming the basis of the forcemoment sensors in accordance with the invention, force moment sensorsconfigured on a larger scale can also be used, for example, in the rangeof mechanical manipulators or in the wrist portion of a robotic hand or,where necessary, also in manipulators as employed in aerospaceapplications.

[0019] Furthermore, the other objective is achieved in accordance withthe invention for a force moment sensor having the features as set forthin claim 10. Advantageous aspects are subjects of the claims 12 and 13.

[0020] In the force moment sensor in accordance with the invention thestrain gauges are mounted on portions along the outer circumference aswell as on connecting webs extending from these portions radially to amiddle portion, whereby the flat tops of the connecting webs are locatedin the same plane as the upper sides of the outer portions.

[0021] Thus, all strain gauges can be mounted in a single plane. Allstrain gauges can be mounted in a single operation and thus withrelatively little expenditure in assembly. Mounting the strain gauges ina single plane eliminates any intersecting or overlapping locations ascould not be excluded in wiring hitherto.

[0022] Mounting the strain gauges in a single plane permits the use of aflexible strip line film to thus eliminate the wires used for contactingthe strain gauges hitherto. In the embodiment in accordance with theinvention the strain gauges can be directly contacted to the flexibleprinted board as flexible strip line connections are formed on thesingle strip lines for contacting by being arranged above, on oralongside to the soldering joints of the strain gauges thus enablingthem to be directly soldered i.e. contacted to the strip line filmwithout any additional wires. Accordingly, the positions of theindividual strip line connections of the flexible strip line film merelyneed to correspond to the positions of the individual strain gauges inone and the same plane.

[0023] In accordance with the invention electronic elements, namely ananalog part in the form of an amplifier or an operational amplifierrespectively and a digital part in the form of an analog/digitalconverter, are provided on the flexible strip line film to thusfurthermore facilitate assembly.

[0024] In accordance with a further preferred embodiment of theinvention for miniaturized force moment sensors smaller than 20 mm indiameter the flexible strip line film may be folded S-shaped, forexample, for accommodating in a correspondingly compact dimensionedsensor housing.

[0025] After assembly of an S-shaped folded strip line film, forexample, the bottommost plane accommodates the strip lines with thestrip line connections contacting the strain gauges, the middle planethe analog part arranged on the film, for example in the form of anoperational amplifier, and the topmost plane the digital part arrangedon the film in general in the form of an analog/digital converter. Inthus not only creating a highly compact configuration but also bylocating the analog part and digital part close together substantiallyreducing the risk of interference, since, only digitized signals arecommunicated outwards.

[0026] The invention will now be explained in detail by way of preferredembodiments with reference to the attached drawings in which:

[0027]FIG. 1 is a top view in perspective representation of the upperside of one embodiment of a force moment sensor;

[0028]FIG. 2 is a view in perspective representation of the underside ofthe force moment sensor as shown in FIG. 1;

[0029]FIG. 3 is a top view of the upper side of the force moment sensoras shown in FIG. 1 including mounted strain gauges representeddiagrammatically;

[0030]FIG. 4a is a top view of roughly a third of the force momentsensor as shown in FIG. 1 including the mounted strain gauges;

[0031]FIG. 4b is a view in perspective representation of the undersidein the part of a force moment sensor as shown in FIG. 4a;

[0032]FIG. 5 is a top view in perspective representation of the upperside of a further embodiment of a force moment sensor;

[0033]FIG. 5a is a view in perspective representation of part of theembodiment of the force moment sensor as shown in FIG. 5 including anend stop;

[0034]FIG. 6 is a view in perspective representation of the underside ofthe force moment sensor as shown in FIG. 5;

[0035]FIG. 7a is a top view of the upper side of roughly a quarter ofthe force moment sensor as shown in FIG. 5;

[0036]FIG. 7b is a view in perspective representation of the undersideof the part of a force moment sensor as shown in FIG. 7a, and

[0037]FIGS. 8a and 8 b are a section view and a top view respectively ofa part of a force moment sensor with mounted strain gauges;

[0038]FIG. 9a is a diagrammatic section through a strip line filmincluding electronic elements provided thereon;

[0039]FIG. 9b is a kind of block diagram of the arrangement as shown insection in FIG. 9a;

[0040]FIGS. 10a to 10 c are illustrations of possible means ofcontacting strip line connections formed on a strip line film;

[0041]FIG. 11 is a diagrammatic illustration, not true to scale, of afolded strip line film accommodated in an indicated sensor housing, and

[0042] FIGS. 12 to 17 are examples of possible circuit arrangements ofstrain gauges circuited on the principle of a Wheatstone bridge as halfor quarter bridges.

[0043] Referring to FIG. 1 and FIG. 2 there is illustrated in each casea view in perspective representation of the upper side and undersiderespectively of a monolithic roughly disk-shaped mounting part 20including a flat surface of a force moment sensor represented on theupper side. In this arrangement the mounting part 20 comprises a firstmiddle portion 21 of high rigidity including first force applicationlocations 25. In a miniaturized embodiment of a force moment sensoralignment pins adapted to apply the forces engage the first forceapplication locations 25, whilst a force application location 25arranged in the middle serves for a screw fastener. Furthermore, themounting part 20 consists of at least three second portions 22 ₁ to 22 ₃of medium rigidity configured circumferentially, each of which isdivided into parts preferably of the same size 22 ₁ a, 22 ₁ b to 22 ₃ a,22 ₃ b, two force application locations 26 each being configuredpreferably at the outer ends in the transition portions (22 ₁, 22 ₂; 22₂, 22 ₃ and 22 ₃, 22 ₁) between the juxtaposed second portions 22 ₁ to22 ₃.

[0044] Configured furthermore in the mounting part 20 between thesub-portions 22 a and 22 b of every second portion 22 are strain reliefportions 23 of low rigidity. At least three connecting webs 24 radiatingradially from the first middle portion 21 of the mounting part 20 areeach joined to the strain relief portions 23 by connections notindicated in detail. These connecting webs 24 of the mounting part 20comprise a medium rigidity achieved by a recess 27 of u-shapedcross-section being configured in the mounting part of each connectingweb 24 as evident from the perspective representation as shown in FIG.2.

[0045] So that the second portions 22 ₁ to 22 ₃ comprise a mediumrigidity, preferably at least one port 29 oriented parallel to the flatsurface is provided between each the force application location 26 andthe strain relief portion 23 in the two sub-portions 22 ₁ a, 22 ₁ b to22 ₃ a, 22 ₃ b.

[0046] Referring now to FIG. 3 there is illustrated how correspondinglyconfigured strain gauges are arranged and mounted on each flat surfaceof the sub-portions 22 a and 22 b of the second portions 22 as well ason the flat surface of the connecting webs 24. In this arrangement onestrain gauge each is mounted oriented at an angle of 45° to an imaginarycentral axis of the connecting webs 24 on each flat surface of theconnecting webs 24. In FIG. 3 the strains/compressions ε of each pair ofstrain gauges mounted on the three webs 24 are indexed 1 and 2, 3 and 4as well as 5 and 6. The indexes 9 to 18 identify each strain/compressionε of the strain gauges attached to the sub-portions 22 a, 22 b of thesecond portions 22 configured in the circumferential portion.

[0047] Shown in FIG. 3 below the disk-shaped mounting part 20 is asystem of Cartesian coordinates. By means of the pairs of strain gauges1 and 2, 3 and 4 as well as 5 and 6 attached to the connecting webs 24the shear stresses produced by the forces F_(x) and F_(y) as well as themoment M_(z) in each connecting web 24 can be sensed. Due to thejuxtaposed sub-portions 22 a and 22 b of adjacent second portions 22 ofmedium rigidity elastic flexural beams are formed such that by means ofthe strain gauges for example 9, 10 and 11, 12 bending stresses areestablished and thus sensed, resulting in the moments M_(x) and M_(y) aswell as the force F.

[0048] Tests have shown that the coupling between the measured values asregards the loads applied is very low. Providing all measuring locationsidentified by the numbers 1 to 18 in a single plane greatly facilitatesmounting the strain gauges. Apart from making use of adhesively bondedstrain gauges, sensing matrices vacuum deposited on the mounting part 20of a force moment sensor, or directly mounted thereon in some other way,may be employed.

[0049] Referring now to FIGS. 4a and 4 b there is illustrated a view ofthe upper side and a perspective representation of the undersiderespectively of a force moment sensor corresponding to roughly a thirdof the disk-shaped mounting part 20 as shown in FIGS. 1 to 3 of a forcemoment sensor. Since in FIGS. 4a and 4 b only roughly a third of theforce moment sensor as shown in FIGS. 1 to 3 is depicted, thecorresponding portions, force application locations as well as themounted strain gauges are identified by the same reference numerals asused in FIGS. 1 to 3 but apostrophized.

[0050] As compared to the sensors as shown in FIGS. 1 to 3 the sensor asshown in FIGS. 4a and 4 b comprises only a restricted functionality.Thus, the “one-third sensor” 20 as indicated in FIGS. 4a and 4 b can beused to sense and measure the forces F_(y) and F_(x) as well as—with acertain lack of accuracy—a moment M_(x).

[0051] Referring now to FIGS. 5 and 6 there is illustrated a top view inperspective representation of the upper side and the undersiderespectively of a further embodiment of a force moment sensor. In theembodiment of the force moment sensor as shown in FIGS. 5 and 6, unlikethe embodiment of the force moment sensor as shown in FIGS. 1 to 3, notonly the at least three components needed to sense the three forces andthe three moments, but in addition a fourth component identical inconfiguration and function is included, as a result of which themeasuring system has in all a redundancy should this prove necessary.However, this redundant embodiment should be realized only in a greaterconstruction. For the miniaturized version of the force moment sensor itis expedient to restrict the configuration to the at least threecomponents as mandatory.

[0052] The embodiment as shown in FIGS. 5 and 6 also depicts the forcemoment sensor configured as a monolithic, roughly disk-shaped mountingpart 30 with a flat surface. The mounting part 30 in turn consists of afirst middle portion 31 of high rigidity including first forceapplication locations 35. Through a port 38 provided at the center ofthe mounting part 30 in the greater construction supply leads or feederscan be guided to the various strain gauges or hardware fitted to thesensor.

[0053] The monolithic mounting part 30 consists furthermore of at leastthree second portions 32 of medium rigidity configuredcircumferentially, at the ends of which second force applicationlocations are each provided, a separate force application location 36being configured in each case, for example, in the greater construction.In the mounting part 30 tab-like strain relief portions 33 areconfigured between the second portions 32 and its outer ends in eachcase in the vicinity of the force application locations 36. Emanatingfurthermore from the middle first portion 31 are four connecting webs 34which in the monolithic configuration are connected to the secondportions 32. These connecting webs 34 comprise in turn a mediumrigidity, achieved, for example, by a recess of u-shaped cross-sectionbeing configured in the middle part of the connecting webs 34 in eachcase, as evident from the underside as shown in FIG. 6.

[0054] Although not shown in detail in the drawings correspondinglyconfigured strain gauges are mounted on the flat surfaces of the secondportions 32 as well as the connecting webs 34 in each case also in thesecond embodiment of a force moment sensor. These strain gauges arecircuited on the principle of a Wheatstone bridge so that from themeasured values sensed in turn three forces F_(x), F_(y) and F_(z) aswell as three moments M_(x), M_(y) and M_(z) are determined.

[0055] In the embodiment as shown in FIGS. 5 and 6 too, the secondportions 32 similar to the second portions 22 of the first embodimentare configured preferably the same in size and preferably with the sameangular space circumferentially. Furthermore, in the second portions 32the specified medium rigidity is achieved by at least two ports 39oriented parallel to the flat surface of the force moment sensor beingconfigured in each case.

[0056] Referring to FIG. 5a there is illustrated only a part, roughly aquarter of the mounting part 30 of the force moment sensor as shown inFIG. 5. Unlike the arrangement as shown in FIG. 5, in FIG. 5a an endstop extending in the radial direction is provided in the form of aalignment pin 40 inserted into the inner flange 31 and protruding with aclearance into a hole 41 drilled in the outer flange 32, as evident fromthe perspective representation as shown in FIG. 5a. Corresponding endstops may also be provided between the remaining connecting webs 34.

[0057] Referring now to FIGS. 7a and 7 b there are illustrated the upperside of a force moment sensor 30 and the underside thereof respectivelyin a top view in perspective representation. The force moment sensor 30′corresponds to roughly a quarter of the disk-shaped mounting part 30 asshown in FIGS. 5 and 6 of the force moment sensor as depicted therein.Since in FIGS. 7a and 7 b only roughly a quarter of the force momentsensor as shown in FIGS. 5 and 6 is depicted, the corresponding portionsand force application locations are identified by the same referencenumerals but apostrophized.

[0058] The same as the sensor as shown in FIGS. 4a and 4 b, the sensorevident from FIGS. 7a and 7 b has only a limited functionality. Thus,for example, with the sensor 20 as shown in FIGS. 7a and 7 b the forcesF_(x) and F_(y), F_(x) respectively as well as a moments M_(x) can besensed and measured, the latter with a certain lack of accuracy.

[0059] Provided on the sub-portions 22 a and 22 b as well as on theconnecting webs 24 of the mounting part 20 of the first embodiment of aforce moment sensor is a total of eighteen strain gauges circuitedpaired in the form of half bridges in accordance with the principle of aWheatstone bridge. In this arrangement, as shown in FIGS. 12, 14 and 16,the strains/compressions ε₁ to ε₆ of the corresponding strain gaugepairs are entered in the two left-hand branches whilst in the remainingbranches of the half-bridges resistors R each dimensioned the same areprovided. The voltages U₁ to U₃ obtained in the diagonals of eachhalf-bridge as shown in FIGS. 12, 14 and 16 are entered in thecorresponding Figures below the corresponding half-bridges in relationto the applied voltage U_(s).

[0060] Referring now to FIGS. 13, 15 and 17 each of thestrains/compressions ε₇ to ε₁₈ of the corresponding pairs of straingauges is entered in the two branches of the Wheatstone bridge. Thevoltages U₄ to U₆ obtained in the diagonals of each half-bridge as shownin FIGS. 13, 15 and 17 are entered in the corresponding Figures belowthe corresponding half-bridges in relation to the applied voltage U_(s).Furthermore, all equations contain amplification factors K.

[0061] Shown by way of example in FIG. 3 is how the correspondinglyconfigured strain gauges 28 mounted on the flat surface of thesub-portions 22 a, 22 b and the connecting webs 24 are circuited on theprinciple of a Wheatstone bridge as half or full bridges for sensing themeasured values corresponding to the strains/contractions produced bythe external loads on the strain gauges.

[0062] Referring now to FIG. 8a there is illustrated in section, forexample, a sub-portion 22 a mounting two strain means in the form ofstrain gauges 28 each of which comprises two soldering joints notindicated in detail, for example in the form of solder pads. FIG. 8b issimply a plan view of the sub-portion 22 a mounting the two straingauges 28 as provided there.

[0063] Referring now to FIG. 9a there is illustrated diagrammatically insection a strip line film 50, the end of which as shown on the right inFIG. 9a is arranged above a strain gauge 28 likewise indicated insection including solder pads thereon (not indicated in detail).Provided to the left of the indicated strain gauge 28 is an analog part54 in the form of one or two amplifiers, more particularly operationalamplifiers. Provided furthermore on one side of the strip line film 50is a digital part 55 to which for example a connector 56 is assigned asa digital interface on the other side of the strip line film. FIG. 9bshows the same elements in the form of a block diagram, the blocklocated on the right indicating contacting of a strain gauge.

[0064] Referring now to FIG. 10a there is illustrated, nottrue-to-scale, strip line connections 52 formed on the strip line film50 whilst indicating how the various strip line connections 52 arecontacted to the solder pads (not indicated in detail) of strain gauges28. Unlike the illustration in FIG. 10a, FIG. 10b illustrates a singlemolded strip line connection 51 at which the strip line 53 as indicatedis contacted by a solder pad of the strain gauge 28.

[0065] As shown in both FIG. 10a and FIG. 10b the strip line connections51 and 52 respectively are molded and oriented so that they are directlylocated above the solder pads of the strain gauges 28 for contacting thelatter. The variant of a strip line connection 51′ as shown in FIG. 10cis configured so that it is arranged to the side of a solder pad of astrain gauge 28 in partly clasping the latter.

[0066] Referring to FIG. 11 there is illustrated diagrammaticallygreatly magnified and not true-to-scale a sensor housing 58accommodating a flexible strip line film 50 folded s-shaped.

[0067] The flexible strip line film 50 is folded so that its bottommostplane as shown in FIG. 11 is arranged above strain gauges 28 mounted ona sub-portion 22 a. Provided in the middle plane of the S-shapedflexible strip line film 50 is the analog part 54, whilst in the topmostplane the digital part 55 and a connector 56 opposite the latter arearranged. Also indicated is a cable output 57.

[0068] In one practical embodiment the sensor housing 58 of aminiaturized force moment sensor has an inner diameter of approximately19 mm and is roughly 10 mm high.

1. A force moment sensor comprising a monolithic disk-shaped mountingpart (20) including a flat surface, said mounting part (20) including afirst middle portion (21) of high rigidity with first force applicationlocations (25), at least three second portions (22 ₁ to 22 ₃) of mediumrigidity each divided into two parts (22 ₁ a, 22 ₁ b to 22 ₃ a, 22 ₃ b)configured circumferentially, each including two second forceapplication locations (26) in the transition portion (22 ₁, 22 ₂; 22 ₂,22 ₃; 22 ₃, 22 ₁) between juxtaposed second portions (22 ₁ to 22 ₃),strain relief portions (23) of low rigidity each configured between thesub-portions (22 ₁ a, 22 ₁ b to 22 ₃ a, 22 ₃ b) and at least threeconnecting webs (24) emanating radially from said first portion (21),each of which is connected by a link to said strain relief portions (23)and comprising a medium rigidity by a recess (27) of U-shapedcross-section being configured on the underside in the medium portionsthereof and on said flat surfaces of said sub-portions (22 a, 22 b) ofsaid second portions (22) and of said connecting webs (24) mountingcorrespondingly configured strain gauges (28) each circuited inaccordance with the principle of a Wheatstone bridge to form quarter,half or full bridges such that from the measured values obtained therebythree forces (F_(x), F_(y), F_(x)) and three moments (M_(x), M_(y),M_(z)) can be defined.
 2. A force moment sensor comprising a monolithicdisk-shaped mounting part (30) including a flat surface, said mountingpart (30) including a first middle portion (31) of high rigidity withfirst force application locations (35), at least three second portions(32) of medium rigidity configured circumferentially at each end ofwhich two second force application locations (36) are configured, strainrelief portions (33) configured at said second portions (32) in saidsecond force application locations (36) and at least three connectingwebs (34) emanating from said first portion (31) and connected to saidsecond portions (32) and featuring medium rigidity by a recess (37) ofu-shaped cross-section being configured on said underside in said mediumportions thereof and on said flat surfaces of said second portions (32)and of said connecting webs (34), mounting correspondingly configuredstrain gauges, each circuited in accordance with the principle of aWheatstone bridge to form quarter, half or full bridges such that fromthe measured values obtained thereby three forces (F_(x), F_(y), F_(z))and three moments (M_(x), M_(y), M_(z)) can be defined.
 3. A forcemoment sensor comprising a monolithic disk-shaped mounting part (20′)including a flat surface, said mounting part (20′) including a firstportion (21′) of high rigidity with first force application locations(25′), a second portion (22′) of medium rigidity divided into twosub-portions (22′a, 22′b), each including a second force applicationlocation (26′) at the outer end of each sub-portion (22′a, 22′b), strainrelief portions (23′) of low rigidity configured between saidsub-portions (22′a, 22′b) and a connecting web (24′) emanating from saidfirst portion (21′), connected by a link to said strain relief portions(23′) and featuring a medium rigidity by a recess (27′) of U-shapedcross-section being configured on the underside in said medium portionthereof and that on said flat surface of said two sub-portions (22′a,22′b) and of said connecting web (24′) correspondingly configured straingauges (28′) are mounted, each circuited in accordance with theprinciple of a Wheatstone bridge to form quarter, half or full bridgessuch that from the measurement values obtained two forces (F_(y), F_(x))can be defined.
 4. A force moment sensor comprising a monolithicmounting part (30′) including a flat surface, said mounting part (30′)including a first portion (31′) of high rigidity with first forceapplication locations (35′), a second portion (32′) of medium rigidityat the ends of which second force application locations (36′) areconfigured, force application locations (33′) in said second portion(32′) at each second force application location (36′), and a connectingweb (34′) emanating from said first portion (31′) connected to saidsecond portion (32′) and comprising a medium rigidity by a recess (37′)of U-shaped cross-section being configured on the underside in themedium portion thereof and that the flat surface of said second portion(32′) and of said connecting web (24′) mount correspondingly configuredstrain gauges (28′) each circuited in accordance with the principle of aWheatstone bridge to form quarter, half or full bridges such that fromthe measurement values obtained two forces (F_(y), F_(x)) can bedefined.
 5. The force moment sensor as set forth in claim 1 or claim 3,wherein said two sub-portion (22 a, 22 b, 22′a, 22′b) of said secondportions (22, 22′) are configured the same in size and in optionalangular spacings circumferentially on said mounting part (20).
 6. Theforce moment sensor as set forth in claim 1 or claim 3, wherein said twosub-portions (22 a, 22 b; 22′a, 22′b) of said second portions (22, 22′)are configured the same in size and in the same angular spacingscircumferentially on said mounting part (20).
 7. The force moment sensoras set forth in any of the claims 1, 3, 5 or 6, wherein said twosub-portions (22 a, 22 b; 22′a, 22′b) of said second portions (22, 22′)have a medium rigidity by at least one port (29;29′) oriented parallelto said flat surface being configured in said two sub-portions betweensaid force application location (26, 26′) and said strain relief portion(23, 23′).
 8. The force moment sensor as set forth in claim 2 or claim4, wherein said second portions (32, 32′) are configured said in samesize and in optional angular spacings circumferentially on said mountingpart (30, 30′).
 9. The force moment sensor as forth in claim 2 or claim4, wherein said second portions (32, 32′) are configured said same insize and in the same angular spacing circumferentially on said mountingpart (30, 30′)
 10. The force moment sensor as set forth in any of theclaims 2, 4, 8 or 9, wherein said second portions (32, 32′) have amedium rigidity by at least two ports (39, 39′) oriented parallel tosaid flat surface being configured in said second portions.
 11. Theforce moment sensor as set forth in any of the claims 1 to 10, whereinon the upper side of said connecting webs (24, 24′, 34, 34′) a straingauge pair (1,2;3,4;5,6) is mounted oriented at an angle of 45° to animaginary central axis of said connecting webs (24, 24′, 34, 34′). 12.The force moment sensor as set forth in any of the claims 1 to 4,wherein arranged above said mounting part (20) is a flexible strip linefilm (50) with strip lines (53) and flexible strip line connections (51,51′, 52) contacting strain gauges (28) mounted on outer portions (22 a,22 b) and portions (24) oriented facing the middle of said mounting part(20) and wherein electronic elements, namely an analog part (54) in theform of an amplifier and a digital part (55) in the form of ananalog/digital converter, are provided.
 13. The force moment sensor asset forth in claim 12, wherein said flexible strip line connections (51,51′, 52) are configured and formed such that they are located directlyabove, on or to the side of solder pads of the corresponding straingauges (28) when said flexible strip line film (50) is arranged above amounting portion (22 a).
 14. The force moment sensor as set forth inclaim 11 or 12, wherein said flexible strip line film (50) is foldeds-shaped in a correspondingly compact dimensioned sensor housing (58)such that its bottommost plane mounts said strip lines (53) with saidcontacted flexible strip line connections (51, 51′, 52), the middleplane mounts said analog part (54) arranged on said flexible strip linefilm and its topmost plane mounts said digital part (55) arrangedsubsequently on said flexible strip line film.
 15. The force momentsensor as set forth in any of said claims 1, 2 or 5 to 11 for use in atleast one finger tip of a robotic hand.
 16. The force moment sensor asset forth in any of the claims 1, 2 or 5 to 11 for use in medicalsystems, more particularly in minimal invasive surgery (MIS).
 17. Theforce moment sensor as set forth in any of the claims 1, 2 or 5 to 11for use in the gripper of a robotic manipulator.
 18. The force momentsensor as set forth in any of the claims 1, 2 or 5 to 11 for use in thewrist portion of a robotic device.
 19. The force moment sensor as setforth in any of the claims 1, 2 or 5 to 11 for use in manipulators inaerospace applications.